In part, the quality of audio that is played back to a listener depends on how the audio was recorded and how the audio was compressed/decompressed (if at all). A playback device can sometimes perform processing during playback, however, to improve the listening experience.
Bass boost is a feature of some audio playback devices. On devices featuring microprocessors, it is often cheaper to implement bass boost in software because analog components, such as capacitors, can have a significant cost.
Many microprocessors in consumer/embedded devices do not feature floating point math capabilities. This presents a challenge when implementing bass boost because traditional filter design techniques tend to yield poles very close to the unit circle for filters whose “action” occurs at very low frequencies. Closeness of the poles to the unit circle means that integer coefficient quantization moves the pole locations, leading to two potential problems: (1) poles may get outside of the unit circle, causing instability; (2) the angle of the poles (in polar coordinates) may change significantly, causing the actual correction frequency to deviate substantially from the intended one.
Therefore, there exists ample opportunity for improvement in technologies related to boosting bass frequencies of audio.